KING ARTHUR had a sister called Morgan le Fay, who was skilled in magic of all sorts, and hated her brother because he had slain in battle a Knight whom she loved. But to gain her own ends, and to revenge herself upon the King, she kept a smiling face, and let none guess the passion in her heart.
One day Morgan le Fay went to Queen Guenevere, and asked her leave to go into the country. The Queen wished her to wait till Arthur returned, but Morgan le Fay said she had had bad news and could not wait. Then the Queen let her depart without delay.
Early next morning at break of day Morgan le Fay mounted her horse and rode all day and all night, and at noon next day reached the Abbey of nuns where King Arthur had gone to rest, for he had fought a hard battle, and for three nights had slept but little. 'Do not wake him,' said Morgan le Fay, who had come there knowing she would find him, 'I will rouse him myself when I think he has had enough sleep,' for she thought to steal his sword Excalibur from him. The nuns dared not disobey her, so Morgan le Fay went straight into the room where King Arthur was lying fast asleep in his bed, and in his right hand was grasped his sword Excalibur. When she beheld that sight, her heart fell, for she dared not touch the sword, knowing well that if Arthur waked and saw her she was a dead woman. So she took the scabbard, and went away on horseback.
When the King awoke and missed his scabbard, he was angry, and asked who had been there; and the nuns told him that it was his sister, Morgan le Fay, who had gone away with a scabbard under her mantle. 'Alas!' said Arthur, 'you have watched me badly!'
'Sir,' said they, 'we dared not disobey your sister.'
'Saddle the best horse that can be found,' commanded the King, 'and bid Sir Ontzlake take another and come with me.' And they buckled on their armour and rode after Morgan le Fay.
They had not gone far before they met a cowherd, and they stopped to ask if he had seen any lady riding that way. 'Yes,' said the cowherd, 'a lady passed by here, with forty horses behind her, and went into the forest yonder.' Then they galloped hard till Arthur caught sight of Morgan le Fay, who looked back, and, seeing that it was Arthur who gave chase, pushed on faster than before. And when she saw she could not escape him, she rode into a lake that lay in the plain on the edge of the forest, and, crying out, 'Whatever may befall me, my brother shall not have the scabbard,' she threw the scabbard far into the water, and it sank, for it was heavy with gold and jewels. After that she fled into a valley full of great stones, and turned herself and her men and her horses into blocks of marble. Scarcely had she done this when the King rode up, but seeing her nowhere thought some evil must have befallen her in vengeance for her misdeeds. He then sought high and low for the scabbard, but could not find it, so he returned unto the Abbey. When Arthur was gone, Morgan le Fay turned herself and her horses and her men back into their former shapes, and said, 'Now, Sirs, we may go where we will.' And she departed into the country of Gore, and made her towns and castles stronger than before, for she feared King Arthur greatly. Meanwhile King Arthur had rested himself at the Abbey, and afterwards he rode to Camelot, and was welcomed by
his Queen and all his Knights. And when he told his adventures and how Morgan le Fay sought his death they longed to burn her for her treason.
The next morning there arrived a damsel at the Court with a message from Morgan le Fay, saying that she had sent the King her brother a rich mantle for a gift, covered with precious stones, and begged him to receive it and to forgive her in whatever she might have offended him. The King answered little, but the mantle pleased him, and he was about to throw it over his shoulders when the lady of the lake stepped forward, and begged that she might speak to him in private. 'What is it?' asked the King. 'Say on here, and fear nothing.' 'Sir,' said the lady, 'do not put on this mantle, or suffer your Knights to put it on, till the bringer of it has worn it in your presence.' 'Your words are wise,' answered the King, 'I will do as you counsel me. Damsel, I desire you to put on this mantle that you have brought me, so that I may see it.' 'Sir,' said she, 'it does not become me to wear a King's garment.' 'By my head,' cried Arthur, 'you shall wear it before I put it on my back, or on the back of any of my Knights,' and he signed to them to put it on her, and she fell down dead, burnt to ashes by the enchanted mantle. Then the King was filled with anger, more than he was before, that his sister should have dealt so wickedly by him.